Hundreds of police officers from across the UK – including South Wales – have been drafted in to help with the Olympics security crisis, which has led to pressure on the head of security firm G4S to quit.

With less than two weeks until the opening ceremony, ministers insisted the London 2012 Games would be secure and dismissed the failure of G4S to provide the promised 10,000 security guards as no more than a “hitch”.

The police officers now being deployed are in addition to the 3,500 servicemen and women who were called in last week.

The South Wales Police Federation (SWPF) blasted the operation as “shambolic” and said officers were being taken away from their core duties to fill in.

Wayne Baker from the SWPF said: “The whole thing has been a complete shambles. Our officers are being deployed either to cover for G4S or on standby in each division.

“Our officers are being taken away from their duties and this has an impact on what they are getting paid to do.”

Mr Baker said officers will still be able to respond to emergency situations but other duties will be delayed, and cancelled days off will affect their personal lives.

He also questioned whether South Wales Police would be reimbursed for the resources lost.

Assistant Commissioner Chris Allison, the National Olympic Security coordinator, said: “Defensive searches, a key part of the Olympic safety and security plan, always needed to be delivered within a tight time frame.

“Our deployments are to ensure that this goes ahead and the plan continues to be delivered.”

Mr Allison added some of the activity undertaken by police officers were “not anticipated” but said plans were put in place to allow such measures.

“Forces are making sure they make the best use of their resources locally to do all they can to minimise the impact on local policing.

“We will continue to work closely with all our partners to get the job done, and these current deployments will be kept under constant review.

“At the present time this is not impacting upon our existing plans for the safety and security operation.”

A South Wales Police spokesman said the force was working closely with Locog, the Games organiser, and G4S and would ensure security and safety in Wales was not compromised.

He said: “South Wales Police officers are supporting the security operation by providing officers to enhance the security arrangements in place, operating to the tight time scales needed to deliver the defensive search regime at athlete facilities in our area.

“Delivering a safe and secure Games is our top priority and we are working closely with our partners to deliver an end-to-end security operation.

“As part of our planning for the Games, we have been sure to build contingency and resilience into our resourcing and we have the capacity to meet this task and we will not compromise on keeping the streets and our local communities safe.”

Meanwhile, armed guards are visible on Cardiff's streets, with security tents set up at the Millennium Stadium and at the city's Hilton hotel, pictured.

The head of G4S is under pressure to quit his £830,000-a-year job as he prepares to face questions from MPs over the Olympics security debacle.

Mr Buckles, pictured, is facing questions from Labour MP Keith Vaz, chairman of the Commons Home Affairs Select Committee, who accused his firm of letting the country down last week.

Mr Buckles, 51, would be entitled to £20 million in pay and benefits if he loses his job over the fiasco which is expected to cause his firm £50 million of losses on the high-profile contract.

Next page: Theresa May facing questions over security shambles

More than £400 million has been wiped off the firm’s value since Wednesday and Home Secretary Theresa May has been forced to appear before MPs twice in the last week over the row.

G4S repeatedly assured ministers it would “overshoot” its recruitment targets and only admitted it would fail last week, she said yesterday.

Mrs May said that despite more than 20,000 security staff being accredited, G4S had problems with scheduling and “getting staff to the venue security tasks”.

Some staff no longer wanted the work, she added.

But Mrs May came under fire from Labour for not knowing how many staff G4S would now provide after the Home Secretary told MPs the “precise balance of the number who will be provided will become clear over the next few days”.

But she denied the firm had “deliberately deceived” the Government.

A total of 3,500 troops, many of whom will be billeted at Tobacco Dock near Wapping, east London, were brought in to make up the shortfall, boosting the number of servicemen and women involved in Games security to 17,000 last week.

Hundreds of officers from eight forces have now also been drafted in to fill gaps.

Venue security was being tightened “before the full complement of accredited staff have been assigned”, a G4S spokesman said.

“This situation is being rectified over the coming days, which should lead to the withdrawal of police officers from those roles assigned to private security.”

Paul Murphy, chairman of Greater Manchester Police Authority, said just 20 of the expected 58 G4S staff turned up at the main Olympic team hotel in Worsley on Saturday to help conduct a “lock-down” of the building.

Mr Murphy told BBC Radio 4’s PM: “Greater Manchester Police had to step in and ensure that the site was properly locked down.

“We have had to use officers and staff on rest days. We have had 28 Pcs and four sergeants into that area, at a cost of £30,000 a day.”

The Police Federation, which represents rank-and-file officers, said the situation was “chaos, absolute chaos”.

Ian Edwards, chairman of the West Midlands branch, said the force is providing 150 officers per day to cover a hotel in Warwickshire where footballers are staying.

“The worst-case scenario is that we end up having to find another 200 officers for the security at the City of Coventry stadium, and we’ve yet to find out what the shortfall is in Birmingham,” he said.

“It’s chaos, absolute chaos.

“You shouldn’t lose your local police officer because of the Olympics. Communities are suffering because a private company has failed to deliver on a contract.”

A confidential report by HM Inspectorate of Constabulary (HMIC) warned about concerns over security 10 months ago, leading Games organisers Locog to increase the number of security guards to be supplied by G4S from 2,000 to 10,400 while the value of the contract more than trebled from £86 million to £284 million.

Reports last night suggested that US security officials will be based at UK airports including Heathrow throughout the Olympic and Paralympic period to assist American-based carriers with security issues.

Sky News reported that the Department for Transport has reached agreement with the US Transportation Security Administration for its officials to be deployed in the UK from next week and to remain until a week after the Paralympic Games end on September 9.

A DfT spokesman said: “The Department for Transport is in regular contact with the US Transportation Security Administration and we have been planning Olympics liaison arrangements with the Americans for several months.

“The department does not comment on the precise details of security matters and these arrangements have nothing whatsoever to do with G4S issue.”

Heathrow airport was also set to handle a record number of passengers yesterday as competitors arrived to take residence in the Olympic village.

The airport expected to handle 236,955 passengers – breaking the previous record of 233,562 set on July 31 last year.

But there were some problems as athletes attempted to travel to the Olympic Village, with current 400m hurdles world champion Dai Greene’s main rival Kerron Clement claiming he spent four hours on a bus after the driver got lost.

“Um, so we’ve been lost on the road for 4hrs. Not a good first impression London,” the American tweeted. “Athletes are sleepy, hungry and need to pee. Could we get to the Olympic Village please.”

He later tweeted to reveal he had finally made it to the Olympic Village and his impression of the UK had improved.

He said: “Eating at the Olympic Village. Love the variety of food choices, African, Caribbean, Halal cuisine, India and Asian and of course McDonald’s.”

Clement’s bus was one of two that went missing, despite the journey supposedly being one that was fast-tracked by the implementation of the Olympic lane on the M4.

A second bus with 30 Australian officials and medical staff were taken past Buckingham Palace and the back streets of West Ham on the lengthy trip to the Olympic Park in Stratford, east London.

London’s transport commissioner Peter Hendy said it was just teething troubles. “If the driver got lost, it tells you nothing about the Games lanes. My information about the current arrivals around Heathrow and the M4 in to London is that they are running very smoothly.

The busiest day for arriving athletes is expected to be July 24, when 1,262 athletes and coaches and 3,008 other Olympics-related arrivals are predicted.

Heathrow operator BAA said immigration waiting times have been within the targets set by the Home Office since new resources were put in place yesterday.

Athletes travel with around twice the number of bags as regular passengers – an average of nearly three items per athlete.

Nick Cole, head of Olympic and Paralympic planning at BAA, said: “[This] heralds the start of Britain’s biggest peacetime transport challenge and Heathrow’s busiest ever period. The Olympic and Paralympic Games are a marathon, not a sprint, for Heathrow.”